The present invention relates to a roll-like photosensitive material packing body (a roll photosensitive material packing body) used for so-called bright room loading.
The roll photosensitive material packing body used for bright room loading is structured such that, for example, the roll photosensitive material is loaded in a magazine or the like, while its light tightness is maintained, and at first exposure, the light tightness is broken in the magazine, and web of the photosensitive material is pulled out from a slit (opening portion) formed in the magazine.
Conventionally, as such a roll photosensitive material packing body, a packing body 20 for roll photosensitive material as shown in FIGS. 19(a) and (b) is disclosed in, for example, Japanese Patent Publication No. 38582/1989. The packing body 20 is composed of roll like photosensitive material 4 in which photosensitive material web 1 is wound around a cylindrical core and which is formed into a roll; disk-like light tight side plates 5 provided on both flat end surfaces 3 of the roll photosensitive material; a belt-like leader 7 jointed to the end of the photosensitive material web 1; and a belt-like light tight cover 6 which covers the outer peripheral surface of the roll photosensitive material 4. The light tight cover 6 is wider than the photosensitive material web 1 and the leader 7, and when it covers the outer peripheral surface of the roll photosensitive material 4, both end portions 8 project in the width direction of the roll photosensitive material 4, and a plurality of slits 9 are provided on its both side ends 8.
On the other hand, other than the above packing body 20, as another example of the conventional packing body, a packing body 30 shown in FIGS. 20(a) and (b), as disclosed in Japanese Utility Model Publication No. 16608/1981, is widely known. The packing body 30 is different from the above-described packing body 20 in the following structural points, and other portions are the same as the above packing body 20: a light tight leader 12 with the light tightness is used instead of the light tight cover 6 used for the above packing body 20; as a light tight means of the end surfaces of the roll photosensitive material, a disk-like end surface cover 15 whose diameter is larger than that of the both end surfaces 14 of the roll photosensitive material 13 and on whose peripheral portion 16 slits 17 are provided, are used for both end surfaces 14; and the peripheral portion 16 on which slits 17 are provided, is bent and cemented along the outer peripheral surface near end portions of the roll photosensitive material 13.
Further, other than the packing bodies 20 and 30, as another example of the conventional packing body, a packing body 40 shown in FIG. 21 is disclosed in Japanese Patent Publication Open to Public Inspection No. 6290/1994. The packing body 40, different from the above-described packing body 30, has no slit on the peripheral portion of the disk-like end surface cover 24, and the disk-like end surface cover 24 is bent and folded along the outer peripheral surface near the end portions of the roll photosensitive material, and is cemented on the outer peripheral surface of the roll photosensitive material.
However, in the conventional packing body 20, when the beginning of the slit 9 coincides with the side end portion of the leader 7, or it is inside the side end portion of the leader 7, there is a possibility that light penetrates from the slit 9 so that the photosensitive material web 1 is fogged, and reversely, when the beginning of the slit 9 is separated too far from the end portion of the leader 7, an effect of cutting is lost. Accordingly, at the production of the packing body 20, adjustment of the positional relationship of the beginning of a plurality of slits 9 formed on both side end portions 8 and the end portion of the leader 7 is very difficult, and in order to process it so that the light does not leak into the inside from the slit, very troublesome operations are necessary in the dimensional adjustment, resulting in an increase of production cost of the packing body 20.
On the other hand, slits 17 formed on the peripheral portions 16 of the both side disk-like end portion covers 15, which are one essential component of the above packing body 30, should be formed so as not to reach the end surface of the roll photosensitive material 13, and therefore, it is necessary that the slits 17 are previously formed by being adjusted to the outer diameter of the roll photosensitive material 13. However, the outer diameter of the roll photosensitive material 13 varies depending on the thickness of the photosensitive material web, winding strength, etc., and therefore, determination of the positions of the slits 17 is also very difficult.
Further, in the packing body 40, it is difficult to obtain the stability to light tightness of the folded portion, and the light enters from the portion into the inside of the packing body, so that the housed photosensitive material is fogged, which is a serious problem.